ax_c_var_func.m4

# ===========================================================================
#      https://www.gnu.org/software/autoconf-archive/ax_c_var_func.html
# ===========================================================================
#
# SYNOPSIS
#
#   AX_C_VAR_FUNC
#
# DESCRIPTION
#
#   This macro tests if the C compiler supports the C9X standard __func__
#   identifier.
#
#   The new C9X standard for the C language stipulates that the identifier
#   __func__ shall be implicitly declared by the compiler as if, immediately
#   following the opening brace of each function definition, the declaration
#
#     static const char __func__[] = "function-name";
#
#   appeared, where function-name is the name of the function where the
#   __func__ identifier is used.
#
# LICENSE
#
#   Copyright (c) 2008 Christopher Currie <christopher@currie.com>
#
#   This program is free software; you can redistribute it and/or modify it
#   under the terms of the GNU General Public License as published by the
#   Free Software Foundation; either version 2 of the License, or (at your
#   option) any later version.
#
#   This program is distributed in the hope that it will be useful, but
#   WITHOUT ANY WARRANTY; without even the implied warranty of
#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
#   Public License for more details.
#
#   You should have received a copy of the GNU General Public License along
#   with this program. If not, see <https://www.gnu.org/licenses/>.
#
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#serial 12

AU_ALIAS([AC_C_VAR_FUNC], [AX_C_VAR_FUNC])
AC_DEFUN([AX_C_VAR_FUNC],
[AC_REQUIRE([AC_PROG_CC])
AC_CACHE_CHECK(whether $CC recognizes __func__, ac_cv_c_var_func,
AC_COMPILE_IFELSE([AC_LANG_PROGRAM([],
[[int main() {
char *s = __func__;
}]])],
[ac_cv_c_var_func=yes],
[ac_cv_c_var_func=no]))
if test "x$ac_cv_c_var_func" = xyes; then
   AC_DEFINE(HAVE_FUNC,,[Define if the C compiler supports __func__])
fi
])dnl